1. Field of the Invention
The present invention relates to a learning device and a learning method for an article transport facility comprising a vehicle configured to move along a travel path, and having a grip portion for gripping an article with the article suspended therefrom, vertical movement means for raising and lowering the grip portion with respect to the vehicle, position adjustment means for adjusting a position of the grip portion horizontally with respect to the vehicle, wherein articles are transferred to and from a transfer support portion located below the travel path by raising and lowering the grip portion with the vehicle stopped at a target stop position in the travel path.
2. Description of the Related Art
In article transport facilities such as one described above, a plurality of transfer support portions are provided along the travel path and the facilities are configured to transport articles among the plurality of the transfer support portions. And when transferring articles to or from each transfer support portion, the grip portion is raised and lowered with respect to the transfer support portion with the vehicle stopped at a target stop position in a travel path. However, when the grip portion is simply raised and lowered with respect to the transfer support portion, the grip portion may become horizontally displaced from the position it is expected to be, due, for example, to inaccuracies in the installation position of the transfer support portion or due to the swaying motion during the raising and lowering of the grip portion. Thus, it is necessary to learn the amount of position adjustment in the horizontal direction for each transfer support portion when raising and lowering the grip portion with respect to the transfer support portion with the vehicle stopped at the target stop position. The learning device and the learning method for the article transport facility in accordance with the present invention are provided to learn such position adjustment amount. And when actually transferring articles to or from each transfer support portion, the position of the grip portion in the horizontal direction is adjusted using the learned position adjustment amount.
A learning device in a conventional article transport facility is provided with a first learn assist member that can be attached to a transfer support portion and that has a detection mark for indicating the position corresponding to the target transfer reference position in the horizontal direction for the transfer support portion with the first learn assist member attached to the transfer support portion, a second learn assist member that the grip portion can grip and that has an imaging means that can capture an image of the area below the grip portion to capture an image of the detection mark with the second learn assist member gripped by the grip portion, and a learning control means—that controls moving operations of the vehicle, vertical movement operations of the vertical movement means, and imaging operations of the imaging means—for learning the amount of position adjustment in the horizontal direction when raising and lowering the grip portion with respect to the transfer support portion with the vehicle stopped at the target stop position for the transfer support portion. And the learning control means moves the vehicle to the target stop position with respect to the transfer support portion, and performs a positioning process in which the grip portion is raised and lowered such that the second learn assist member gripped by the grip portion, with the second learn assist member adjusted to the standard adjustment position, is located at a target height with respect to the first learn assist member attached to the transfer support portion. The standard adjustment position is, for example, a position in which the center of the grip portion coincides with the center of the vehicle in the lateral direction of the vehicle, and in which the lateral direction and the fore and aft direction of the grip portion coincide with the lateral direction and the fore and aft direction of the vehicle in the angular direction about a vertical axis. After the positioning process, the learning control means is configured to perform an image capturing process in which the imaging means is caused to capture an image of the detection mark, and to perform a deviation amount calculating process in which a reference position deviation amount in the horizontal direction between the imaging reference position set in the center of the field of view of the image and the detection mark is derived based on the image information captured in the image capturing process to calculate the position adjustment amount from the derived reference position deviation amount. (See, for example, Patent Document 1.)    Patent Document 1: Japanese Patent Application Publication No. 2003-192269